Prospecting Herkimer Diamond crystals in Little Falls, NY. These quartz crystals are unique due to their exceptional clarity, natural faceting, and distinct double terminated ends (pointed ends). These crystals are typically found in dolostone rock formations that date back to the Cambrian period. Unlike most quartz crystals that grow attached to a host rock and have only one termination, Herkimer Diamonds form freely in pockets of dolostone, resulting in their double-terminated shape. The natural facets of Herkimer Diamonds usually consist of 6 sides and 18 total facets. This makes these stones look cut and polished, even though they are completely natural.